Power on the unit and tap the icon on the home screen. Navigate to the General or System tab. Scroll down to find the Factory Default or Reset option.
If the display is blank or the unit is unresponsive, disconnect the vehicle's battery for approximately 5–10 minutes. This forces the internal capacitors to drain and restarts the hardware from scratch. Settings Menu Reset: If you can still access the screen: Factory Reset Restore Default Settings grundig gx-3800 factory reset code
Once you recover or reset the code, write it down inside your car's glove box or save it in your phone's notes. Power on the unit and tap the icon on the home screen